The name "Koehn" in my family was originally spelled in German writing as "K÷hn" which in English pronunciation is like "Kane". The umlaut over the "o" is usually replaced with "oe" when converted to the English language but the pronunciation sound is changed. This does not necessarily mean that my German ancestors had that name, K÷hn, because sometimes when immigrants arrived in America the name was transcribed phonetically by immigration officials who had limited or no knowledge of the German language. Names were often written in different spellings as originally intended. Since I am not aware of who my ancestors are beyond my great grandfather, John Carl Martin Koehn, then "Koehn" may just be a Germanization of a Jewish name Kohen or Cohen which meant 'Priest. A cousin of mine has told me that information from his family indicates this may be the case in our family tree.
Four children were known to have been born in Germany. Johns wife, Louise Voss (Vo▀), and her family are well documented. An outline of this family can be found on this site.
Any further information on the Koehn ancestry is welcome.